Author(s): Liu, ZH (Liu, Zehua); Li, JZ (Li, Jingzhen); Zhang, L (Zhang, Ling); Zhang, Y (Zhang, Yu); Yang, S (Yang, Song); Bai, ZX (Bai, Zhenxu); Wang, YL (Wang, Yulei); Lu, ZW (Lu, Zhiwei); Yan, DP (Yan, Dapeng); Qi, YY (Qi, Yaoyao); Zhang, XW (Zhang, Xingwang)

Source: ADVANCED OPTICAL MATERIALS DOI: 10.1002/adom.202401165  Early Access Date: JUL 2024  Published Date: 2024 JUL 3  

Abstract: Ultrafast vortex beams have significant scientific and practical value because of their unique phase properties in both the longitudinal and transverse modes, enabling multi-dimensional quantum control of light fields. Directly generating watt-level ultrafast vortex beams with large angular momentum has remained a major challenge due to the limitations of mode-locked materials and existing spatiotemporal mode-locking generation methods. In this study, quasi-2D PEA(2)(CsPbBr3)(n-1)PbBr4 perovskite films are prepared by an anti-solvent method and employed for the first time in a mode-locked resonator operating in free space. Utilizing the angle-based non-collinear pumping and frequency doubling techniques, the second-order ultrafast green vortex beams with a power of up to 1.05 W and a duration of 373 ps are generated. Experimental findings demonstrate the strong nonlinear saturable absorption properties of quasi-2D PEA(2)(CsPbBr3)(n-1)PbBr4 perovskite films at high power levels, highlighting their considerable potential in ultrafast laser technology and nonlinear optics.